Signal tracking method and system of satellite navigation system receiver

Abstract

The invention relates to the technical field of satellite navigation, and discloses a signal tracking method and system for a satellite navigation system receiver, and the method comprises the steps: obtaining a local carrier signal according to a carrier phase residual error at a previous moment, and carrying out the coherent integration processing of an intermediate frequency carrier signal, and obtaining a coherent integration value; according to the coherent integral value, establishing a carrier signal state model and a carrier signal observation model of extended Kalman filtering of the intermediate frequency carrier signal, and performing extended Kalman filtering iterative calculation on the coherent integral value to obtain a state vector estimated value of the intermediate frequency carrier signal; and performing multi-channel carrier signal joint tracking on the coherent integral value corresponding to the intermediate frequency carrier signal of each antenna array element, and obtaining a carrier phase residual error at the current moment according to the obtained dynamic phase weight value so as to correct the phase of the corresponding state vector estimation value to obtain a carrier signal phase estimation value. According to the method, the signal tracking precision of the satellite navigation system receiver is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite navigation system, and particularly relates to a signal tracking method and system of a satellite navigation system receiver. BACKGROUND

[0002] The satellite navigation system has the outstanding advantages of high-precision positioning and high-reliable timing. However, in the actual application process, the signal transmission and reception link of the satellite navigation system has significant vulnerability and limitation. On the one hand, when the satellite signal is transmitted from the outer space to the ground receiver, the signal strength is weak and is easily affected by the complex electromagnetic environment. At present, the number of various electronic devices (such as communication base stations, industrial control devices, consumer electronics, etc.) is growing explosively. The electromagnetic signals generated when a large number of electronic devices are running are superimposed on each other, forming a dense electromagnetic interference environment, which makes it difficult for the satellite navigation receiver antenna to capture the target navigation signal meeting the quality requirements, and even may be deceived by the fake interference signal, causing positioning deviation, timing failure and other problems, which seriously threatens the safety of the application system relying on satellite navigation. On the other hand, the complex application scenarios such as urban high-rise building dense areas, forest coverage areas and canyon areas are increasing. In such scenarios, the obstacles such as buildings, trees and terrain will cause serious channel shielding to the satellite signal, resulting in signal interruption or aggravation of multipath effect, further reducing the signal reception quality and working stability of the satellite navigation receiver.

[0003] In the prior art, the array signal processing technology is mainly used in the satellite navigation receiver to overcome interference. The signal processing logic of the traditional antenna array receiver is mostly set as: before the satellite intermediate frequency carrier signal enters the baseband processing module, the adaptive array processing operation is first performed on the intermediate frequency carrier signal. The processing operation usually includes key steps such as beam forming and null suppression, so as to improve the signal gain and suppress the multipath interference signal. However, the traditional antenna array receiver has great dependence on external information sources, and is not suitable for the increasingly complex signal environment. The signal tracking estimation accuracy is low.

[0004] Therefore, how to improve the signal tracking accuracy of the satellite navigation system receiver has become a technical problem to be solved by those skilled in the art. SUMMARY

[0005] The present application provides a signal tracking method and system of a satellite navigation system receiver, to solve the technical problem of how to improve the signal tracking accuracy of the satellite navigation system receiver, and to achieve the effect of improving the signal tracking accuracy of the satellite navigation system receiver.

[0006] In a first aspect, the present application provides a signal tracking method of a satellite navigation system receiver, the method comprising: According to the carrier phase residual of each antenna array element at the last time, a local carrier signal is obtained, and coherent integration processing is performed on the intermediate frequency carrier signal output by each antenna array element according to the local carrier signal, to obtain a coherent integration value of each intermediate frequency carrier signal. According to the coherent integration value, a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal are established, and based on the carrier signal state model and the carrier signal observation model, the coherent integration value is iteratively calculated by the extended Kalman filter, to obtain a state vector estimation value of each intermediate frequency carrier signal. Based on the local carrier signal, the coherent integration value is jointly tracked by a multi-channel carrier signal, to obtain a dynamic phase weight value of each antenna array element. According to the dynamic phase weight value, the carrier phase residual of each antenna array element at the current time is obtained, and the phase of the corresponding state vector estimation value is corrected according to the carrier phase residual at the current time, to obtain a carrier signal phase estimation value of the intermediate frequency carrier signal.

[0007] Preferably, the coherent integration processing on the intermediate frequency carrier signal output by each antenna array element according to the local carrier signal to obtain the coherent integration value of each intermediate frequency carrier signal comprises: According to the local carrier signal, target signal extraction and phase alignment are performed on the intermediate frequency carrier signal output by each antenna array element, to obtain a baseband complex signal; The complex domain superposition is performed on each baseband complex signal, to obtain the coherent integration value of each intermediate frequency carrier signal.

[0008] Preferably, the establishment of the carrier signal state model and the carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal according to the coherent integration value comprises: The state vector and the state transition matrix of the intermediate frequency carrier signal are established, and the state vector and the state transition matrix are converted into a carrier signal state equation of the extended Kalman filter; according to the integration time, the intermediate frequency carrier signal angular frequency, and the power spectrum intensity of the state driving noise of the numerically controlled oscillator, a state noise covariance matrix is established; According to the carrier signal state equation and the state noise covariance matrix, a carrier signal state model is constructed; According to the coherent integration value, a carrier signal observation equation of the extended Kalman filter is set; and according to the carrier-to-noise ratio of the intermediate frequency carrier signal, an observation noise covariance matrix is set; According to the carrier signal observation equation and the observation noise covariance matrix, a carrier signal observation model is constructed.

[0009] Preferably, the setting the carrier signal observation equation of the extended Kalman filter according to the coherent integration value comprises: obtaining a branch coherence matrix according to the coherent integration value, the integration time and the carrier phase of the intermediate frequency carrier signal; obtaining an observation noise matrix according to the co-directional observation noise of the co-directional branch and the quadrature observation noise of the quadrature branch according to the coherent integration value; setting the carrier signal observation equation of the extended Kalman filter according to the branch coherence matrix and the observation noise matrix.

[0010] Preferably, the performing the extended Kalman filter iterative calculation on the coherent integration value based on the carrier signal state model and the carrier signal observation model to obtain the state vector estimation value of each intermediate frequency carrier signal comprises: obtaining a single-step state prediction value and a priori error variance matrix of a current time according to the state noise covariance matrix, the carrier signal state equation, the state vector estimation value of a last time and the a posteriori error variance matrix of the last time; obtaining a linearized observation matrix after the linearized observation function after the performing the conversion on the coherent integration value according to the carrier signal observation equation; obtaining a Kalman gain according to the a priori error variance matrix, the observation noise covariance matrix and the linearized observation matrix; obtaining the state vector estimation value of the current time according to the single-step state prediction value, the Kalman gain, the carrier signal observation equation and the linearized observation matrix, and estimating the a posteriori error variance matrix of the current time according to the Kalman gain, the linearized observation matrix and the a priori error variance matrix to obtain the a posteriori error variance matrix of the current time.

[0011] Preferably, the linearized observation matrix is set as a matrix about the coherent integration value, the integration time, the total number of antenna array elements and the local carrier signal phase estimation value.

[0012] Preferably, the performing the multi-channel carrier signal joint tracking on the coherent integration value based on the local carrier signal to obtain the dynamic phase weight value of each antenna array element comprises: obtaining an initial reference signal of each antenna array element according to the coherent integration value, and obtaining an initial phase weight value of the coherent integration value according to the initial reference signal; performing dynamic iterative update on the initial reference signal according to the local carrier signal and the initial phase weight value to obtain a dynamic reference signal of each antenna array element at a current time; The initial phase weight value is dynamically iteratively updated based on the dynamic reference signal at the current moment, to obtain a dynamic phase weight value of each antenna array element at the current moment.

[0013] Preferably, the carrier phase residual of each antenna array element at the current moment is obtained according to the dynamic phase weight value, and the carrier phase residual at the current moment is used to include: The intermediate frequency carrier signal of any antenna array element is cross-correlated with a combined reference signal constructed by weighted combination of the remaining antenna array elements; The phase difference between the intermediate frequency carrier signal and the combined reference signal is extracted to obtain the carrier phase residual of each antenna array element at the current moment.

[0014] Preferably, the phase of the corresponding state vector estimate value is corrected according to the carrier phase residual at the current moment to obtain a carrier signal phase estimate value of the intermediate frequency carrier signal, including: The phase sum between the carrier phase residual at the current moment and the corresponding state vector estimate value is calculated to obtain a carrier signal phase estimate value of the intermediate frequency carrier signal.

[0015] In a second aspect, the application provides a signal tracking system of a satellite navigation system receiver, which implements the signal tracking method of the satellite navigation system receiver described above, and the system includes a coherent integration processing module, an extended Kalman filtering processing module, a phase weight value dynamic updating module and a phase correction module. The coherent integration processing module is used to obtain a local carrier signal according to the carrier phase residual of each antenna array element at the previous moment, and to perform coherent integration processing on the intermediate frequency carrier signal output by each antenna array element according to the local carrier signal, to obtain a coherent integration value of each intermediate frequency carrier signal. The extended Kalman filtering processing module is used to establish a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filtering of the intermediate frequency carrier signal according to the coherent integration value, and to perform extended Kalman filtering iterative calculation on the coherent integration value based on the carrier signal state model and the carrier signal observation model, to obtain a state vector estimate value of each intermediate frequency carrier signal. The phase weight value dynamic updating module is used to perform multi-channel carrier signal joint tracking on the coherent integration value based on the local carrier signal, to obtain a dynamic phase weight value of each antenna array element. The phase correction module is configured to obtain the carrier phase residual of each antenna array element at the current time according to the dynamic phase weight value, and correct the phase of the corresponding state vector estimation value according to the carrier phase residual at the current time to obtain the carrier signal phase estimation value of the intermediate frequency carrier signal.

[0016] The application provides a signal tracking method and system of a satellite navigation system receiver, and has the following beneficial effects compared with the prior art: The application divides the signal carrier phase change into common carrier phase caused by satellite movement and residual carrier phase caused by position difference of the array antenna, and tracks them respectively, thereby improving the accuracy of signal carrier phase estimation in a complex electromagnetic environment, optimizing and adjusting the single-channel signal tracking loop structure of the antenna array element, improving the tracking sensitivity of each array element to the received signal, improving the tracking performance of weak signals in an interference environment, and converting the joint processing of the spatial signals of the antenna array from the level of intermediate frequency signal processing to baseband signal processing, thereby avoiding the calculation amount and hardware resource consumption caused by large bandwidth and high precision in intermediate frequency signal processing. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a satellite navigation system receiver signal tracking method step schematic diagram provided by a preferred embodiment of the application; Figure 2 is a satellite navigation system receiver signal tracking system structure schematic diagram provided by a preferred embodiment of the application; REFERENCE NUMERALS: 1-coherent integration processing module, 2-extended Kalman filtering processing module, 3-phase weight value dynamic updating module, 4-phase correction module. DETAILED DESCRIPTION

[0018] The embodiments of the application are specifically described below with reference to the drawings, and the embodiments are given only for illustrative purposes, and cannot be understood as limiting the application. The accompanying drawings are only for reference and illustration, and do not constitute a limitation on the protection scope of the patent of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0019] In the description of the present application, it is to be noted that the term "and / or" as used herein is used to include one or more recited items which are co ncatenated with "and / or". The specific meaning of the term "and / or" in the present application can be understood in the light of the specific circumstances by those skilled in the art.

[0020] In the description of the present application, it is to be noted that unless otherwise defined and limited, all the technical and scientific terms used in the present application have the same meaning as that generally understood by those skilled in the art. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The specific meaning of the above-mentioned terms in the present application can be understood in the light of the specific circumstances by those skilled in the art.

[0021] Please refer to Figure 1 As shown in a step schematic diagram of a signal tracking method of a satellite navigation system receiver, in the embodiments of the present application, a signal tracking method of a satellite navigation system receiver is provided, and the method comprises: S1, according to the obtained carrier phase residual of each antenna array element at the last time, a local carrier signal is obtained, and a coherent integration processing is performed on the intermediate frequency carrier signal output by each antenna array element according to the local carrier signal, to obtain a coherent integration value of each intermediate frequency carrier signal; in the preferred embodiments of the present application, a weak signal anti-jamming tracking method based on extended Kalman filtering is proposed, which is used for tracking the intermediate frequency carrier signals captured by each antenna array element in the antenna array. The control digital controlled oscillator outputs a local carrier signal based on the carrier phase residual at the last time, and performs coherent integration processing on the intermediate frequency carrier signal output by each antenna array element according to the local carrier signal. Coherent integration processing is a key signal processing technology for improving signal-to-noise ratio by using "signal phase consistency", and the core is to superimpose multiple received signals under the premise of "preserving signal phase information", so as to enhance the useful signal and suppress random noise. Specifically, through the phase adjuster, the intermediate frequency carrier signal output by the radio frequency front end of each antenna array is subjected to target signal extraction, and the extracted signal is subjected to phase alignment by using the local carrier signal, to obtain a baseband complex signal. Since the phase information of the signal needs to be represented by a complex number, the real part is the amplitude, and the imaginary part is the phase, so the baseband complex signal is superimposed in the complex domain to obtain a coherent integration value. In the complex domain superposition, the pseudo-code signal of the satellite navigation system in the intermediate frequency carrier signal is aligned with the local carrier signal, and is enhanced according to the linear relationship of the superposition number after complex superposition. The random noise in the intermediate frequency carrier signal is enhanced according to the law of the superposition number after complex superposition because of the random phase, and the signal-to-noise ratio of the finally output coherent integration value is greatly improved compared with the intermediate frequency carrier signal output by a single antenna array element.

[0022] S2 establishes a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal based on the coherent integral value, and performs extended Kalman filter iterative calculation on the coherent integral value based on the carrier signal state model and the carrier signal observation model to obtain the state vector estimate of each intermediate frequency carrier signal; In a preferred embodiment of this application, the signal tracking method of the satellite navigation system receiver includes a single-channel carrier signal tracking stage and a multi-channel carrier signal joint tracking stage. For the single-channel carrier signal tracking stage, an extended Kalman filter is used to replace the maximum likelihood estimator, and an extended Kalman filter carrier signal state model and a carrier signal observation model are established. The carrier signal state model includes a carrier signal state equation and a state noise covariance matrix. For the carrier signal state equation, a state vector and a state transition matrix of the intermediate frequency carrier signal are established. The change process of the state vector value is expressed as follows: in, express The carrier phase of the intermediate frequency carrier signal at a given time. express The carrier Doppler frequency shift of the intermediate frequency carrier signal at a given time. express The rate of change of the carrier Doppler frequency of the intermediate frequency carrier signal at time t. , and They represent ( The higher-order terms after performing a Taylor expansion on the intermediate frequency carrier signal at time ) Indicates the integration time.

[0023] The change process of the above state vector values ​​is modeled as the carrier signal state equation of the extended Kalman filter, which is expressed as: in, express Error state quantity at time t. express( Error state quantity at time ) express( The carrier Doppler frequency shift of the intermediate frequency carrier signal at time ) express( The rate of change of the carrier Doppler frequency of the intermediate frequency carrier signal at time ) , , This represents the state-driven noise of the numerically controlled oscillator. It is white noise from the random phase walk of the clock crystal oscillator. It is white noise with random walk at the clock crystal frequency. is a clock crystal frequency noise, denotes Doppler frequency shift of the local carrier signal before the extended Kalman filter ends.

[0024] Further, according to the integral time, the intermediate frequency carrier signal angular frequency, the power spectral intensity of the state driven noise of the extended Kalman filter, a state noise covariance matrix is established, and the state noise covariance matrix is represented as: wherein, denotes the angular frequency of the intermediate frequency carrier signal at the time, denotes the power spectral intensity of, denotes the power spectral intensity of, denotes the power spectral intensity of.

[0025] The carrier signal observation model includes a carrier signal observation equation and an observation noise covariance matrix, and the carrier signal observation equation is represented as: wherein, denotes the observation value output by the phase discriminator of the coherent integration value, denotes the first observation value in the in-phase branch at the time, denotes the second observation value in the quadrature branch at the time, denotes the same direction observation noise in the in-phase branch at the time, denotes the quadrature observation noise in the quadrature branch at the time.

[0026] wherein, denotes the first coherent integration value in the in-phase branch at the time, denotes the second coherent integration value in the quadrature branch at the time.

[0027] wherein, denotes the observation noise matrix at the time, which is set to 1ms.

[0028] According to the carrier-to-noise ratio of the intermediate frequency carrier signal, the observation noise covariance matrix is set, and the observation noise covariance matrix is represented as: wherein, denotes the carrier-to-noise ratio of the intermediate frequency carrier signal, denotes a two-dimensional identity matrix.

[0029] Further, based on the carrier signal state model and the carrier signal observation model, the coherent integration value is iteratively calculated by an extended Kalman filter to obtain a state vector estimation value and a posteriori error variance matrix. Specifically, according to a state noise covariance matrix of the carrier signal state model, a carrier signal state equation of the carrier signal state model, a state vector estimation value at a previous time and a posteriori error variance matrix at the previous time, a single-step state prediction value at a current time and a priori error variance matrix are obtained, and the calculation formula is as follows: wherein, denotes a state vector estimation value at the time t, denotes a priori error variance matrix at the time t, denotes a single-step state prediction value at the time t, denotes a priori error variance matrix at the time t. The single-step state prediction value denotes a priori state estimation of the current state obtained by only using the process prior knowledge without considering the process noise.

[0030] After the linearized observation matrix after the linearized observation function is obtained by converting the coherent integration value according to the carrier signal observation equation of the carrier signal observation model, the linearized observation matrix is denoted as: wherein, denotes a linearized observation matrix at the time t, denotes the total number of antenna array elements, denotes a phase estimation value of the local carrier signal at the time t, denotes the observation noise of the intermediate frequency carrier signal.

[0031] Further, the Kalman gain is obtained according to the priori error variance matrix, the observation noise covariance matrix of the carrier signal observation model and the linearized observation matrix, and the Kalman gain is denoted as: wherein, denotes the Kalman gain.

[0032] Based on the single-step state prediction value, Kalman gain, carrier signal observation equation, and linearized observation matrix, the coherent integral value is estimated to obtain the estimated state vector value at the current time, as shown below: in, express State vector estimate at time t. Based on the Kalman gain, the linearized observation matrix, and the prior error variance matrix, the posterior error variance matrix of the previous time step is estimated to obtain the posterior error variance matrix of the current time step, as shown below: in, express The prior error variance matrix at time t.

[0033] In the preferred embodiment of this application, the common carrier phase estimation is performed using extended Kalman filtering, achieving the optimal estimation result and exhibiting excellent filtering performance.

[0034] S3. Based on the local carrier signal, perform multi-channel carrier signal joint tracking on the coherent integral value to obtain the dynamic phase weight value of each antenna element. In a preferred embodiment of this application, for the multi-channel carrier signal joint tracking stage, a reference signal is generated by a signal synthesis method, and the average phase value and average frequency are estimated to integrate the tracking results of all channels. Specifically, based on the coherent integral value, an initial reference signal for each antenna element is obtained, and based on the initial reference signal, the initial phase weight value of the coherent integral value is obtained. The initial reference signal is represented as follows: in, Represents antenna array elements The conjugate of the coherent integral values.

[0035] Based on the local carrier signal and the initial phase weight value, the initial reference signal is dynamically iteratively updated to obtain the dynamic reference signal for each antenna element at the current moment. The expression for updating the dynamic reference signal is: in, express Dynamic reference signal at any given time, This indicates the antenna element number used to calculate the reference signal. express Time antenna array element The complex conjugate of the intermediate frequency carrier signal, In addition to the array elements The numbering of other antenna array elements besides express Time antenna array element The dynamic phase weight value, express The local carrier signal at any given time.

[0036] Furthermore, based on the dynamic reference signal at the current moment, the initial phase weight value is dynamically iteratively updated to obtain the dynamic phase weight value of each antenna element at the current moment. The update formula for the dynamic phase weight value at the current moment is: in, express Time antenna array element The dynamic phase weight value, express Time Array Element The intermediate frequency carrier signal at that location, express Time antenna array element The complex conjugate of the dynamic phase weight value, Represents antenna array elements The number of sampling points for cross-correlation calculation.

[0037] S4. Based on the dynamic phase weight value, obtain the carrier phase residual of each antenna element at the current moment, and based on the carrier phase residual at the current moment, correct the phase of the corresponding state vector estimate to obtain the carrier signal phase estimate of the intermediate frequency carrier signal; In a preferred embodiment of this application, by cross-correling the intermediate frequency carrier signal received by one of the wire array elements with the combined reference signal constructed by the weighted combination of the other wire array elements in the wire array, extract its phase difference value to obtain the carrier phase residual of the wire array element relative to the array center, and the carrier phase residual is expressed as follows: in, express Time antenna array element carrier phase residual, This indicates the extraction of the phase angle.

[0038] Furthermore, based on the carrier phase residual of each intermediate frequency carrier signal, the corresponding state vector estimate is corrected to obtain the carrier signal phase estimate of the intermediate frequency carrier signal, which is expressed as: in, express Time antenna array element The estimated phase value of the carrier signal. express antenna element phase of the state vector estimate.

[0039] In the preferred embodiment of the application, according to the obtained carrier phase residual of each antenna element at the previous time, a local carrier signal is obtained, and coherent integration processing is performed on the intermediate frequency carrier signal output by each antenna element according to the local carrier signal, to obtain a coherent integration value of each intermediate frequency carrier signal; according to the coherent integration value, a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal are established, and based on the carrier signal state model and the carrier signal observation model, the coherent integration value is iteratively calculated by the extended Kalman filter, to obtain a state vector estimate of each intermediate frequency carrier signal; based on the local carrier signal, the coherent integration value is jointly tracked by multiple channel carrier signals, to obtain a dynamic phase weight value of each antenna element; according to the dynamic phase weight value, a carrier phase residual of each antenna element at the current time is obtained, and the phase of the corresponding state vector estimate is corrected according to the carrier phase residual at the current time, to obtain a carrier signal phase estimate of the intermediate frequency carrier signal. The signal tracking method of the satellite navigation system receiver disclosed in the application divides the signal carrier phase change into a common carrier phase caused by satellite motion and a residual carrier phase caused by the position difference of the array antenna, and respectively tracks the common carrier phase and the residual carrier phase, thereby improving the accuracy of the signal carrier phase estimation in a complex electromagnetic environment. The signal tracking loop structure of a single channel in the antenna element is optimized and adjusted, the tracking sensitivity of each channel to the received signal is improved, the tracking performance of the weak signal in the interference environment is improved, the spatial signal joint processing of the antenna array is converted from the intermediate frequency signal processing level to the baseband signal processing, and the calculation amount and the consumption of hardware resources caused by high precision in the intermediate frequency signal processing are avoided.

[0040] Correspondingly, as shown in Figure 2 the structural schematic diagram of the signal tracking system of the satellite navigation system receiver, based on the signal tracking method of the satellite navigation system receiver, the embodiment of the application further provides a signal tracking system of a satellite navigation system receiver, which implements the signal tracking method of the satellite navigation system receiver disclosed in the embodiment of the application. The system comprises a coherent integration processing module 1, an extended Kalman filter processing module 2, a phase weight value dynamic updating module 3 and a phase correction module 4. The coherent integration processing module 1 is configured to obtain a local carrier signal according to the obtained carrier phase residual of each antenna element at the previous time, and perform coherent integration processing on the intermediate frequency carrier signal output by each antenna element according to the local carrier signal, to obtain a coherent integration value of each intermediate frequency carrier signal. The extended Kalman filter processing module 2 is configured to establish a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal according to the coherent integration value, and perform extended Kalman filter iterative calculation on the coherent integration value based on the carrier signal state model and the carrier signal observation model, so as to obtain a state vector estimation value of each intermediate frequency carrier signal. The phase weight value dynamic updating module 3 is configured to perform multi-channel carrier signal joint tracking on the coherent integration value based on the local carrier signal, so as to obtain a dynamic phase weight value of each antenna array element. The phase correction module 4 is configured to obtain the carrier phase residual of each antenna array element at the current time according to the dynamic phase weight value, and correct the phase of the corresponding state vector estimation value according to the carrier phase residual at the current time, so as to obtain a carrier signal phase estimation value of the intermediate frequency carrier signal.

[0041] The specific limitation of the signal tracking system of the satellite navigation system receiver can refer to the above limitation of the signal tracking method of the satellite navigation system receiver, which will not be repeated here. Those skilled in the art can realize that the various modules and steps described in combination with the embodiments disclosed in the present application can be realized in hardware, software or combination of both. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0042] In conclusion, the signal tracking method and system of the satellite navigation system receiver provided by the embodiments of the present application solve the technical problem of how to improve the signal tracking precision of the satellite navigation system receiver, and the method comprises the following steps: obtaining a local carrier signal according to the carrier phase residual of each antenna array element at the previous time, and performing coherent integration processing on the intermediate frequency carrier signal output by each antenna array element according to the local carrier signal to obtain the coherent integration value of each intermediate frequency carrier signal; establishing a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal according to the coherent integration value, and performing extended Kalman filter iterative calculation on the coherent integration value based on the carrier signal state model and the carrier signal observation model to obtain the state vector estimation value of each intermediate frequency carrier signal; performing multi-channel carrier signal joint tracking on the coherent integration value based on the local carrier signal to obtain the dynamic phase weight value of each antenna array element; obtaining the carrier phase residual of each antenna array element at the current time according to the dynamic phase weight value, and correcting the phase of the corresponding state vector estimation value according to the carrier phase residual at the current time to obtain the carrier signal phase estimation value of the intermediate frequency carrier signal. The signal tracking method of the satellite navigation system receiver disclosed in the present application divides the signal carrier phase change into the common carrier phase caused by satellite motion and the residual carrier phase caused by the position difference of the array antenna, and tracks them respectively, thereby improving the precision of the signal carrier phase estimation in the complex electromagnetic environment, optimizing and adjusting the single-channel signal tracking loop structure of the antenna array element, improving the tracking sensitivity of each antenna element to the received signal, improving the tracking performance of the weak signal in the interference environment, and converting the spatial signal joint processing of the antenna array from the intermediate frequency signal processing level to the baseband signal processing, thereby avoiding the calculation amount and hardware resource consumption caused by the large bandwidth and high precision in the intermediate frequency signal processing.

[0043] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts of each embodiment can be referred to each other. Each embodiment focuses on the difference from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, it is described more simply, and the related parts can be referred to the part of the method embodiment. It should be noted that, each technical feature of the above-mentioned embodiments can be combined arbitrarily, in order to make the description simple, not all possible combinations of the technical features in the above-mentioned embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0044] The above-described embodiments are merely illustrative of several preferred embodiments of the present application, which are described in more detail and in a more specific and detailed manner, but should not be construed as limiting the scope of the patent application. It should be noted that for those skilled in the art, several improvements and replacements can be made without departing from the technical principles of the present application, and these improvements and replacements should also be considered as the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the protection scope of the claims.

Claims

1. A signal tracking method for a satellite navigation system receiver, characterized in that, The method includes: Based on the carrier phase residual of each antenna element obtained at the previous moment, the local carrier signal is obtained, and based on the local carrier signal, the intermediate frequency carrier signal output by each antenna element is coherently integrated to obtain the coherent integral value of each intermediate frequency carrier signal. Based on the coherent integral value, a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal are established. Based on the carrier signal state model and the carrier signal observation model, the extended Kalman filter is iteratively calculated on the coherent integral value to obtain the state vector estimate of each intermediate frequency carrier signal. Based on the local carrier signal, the coherent integral value is jointly tracked by multiple channels of carrier signals to obtain the dynamic phase weight value of each antenna element. Based on the dynamic phase weight value, the carrier phase residual of each antenna element at the current moment is obtained, and the phase of the corresponding state vector estimate is corrected based on the carrier phase residual at the current moment to obtain the carrier signal phase estimate of the intermediate frequency carrier signal.

2. The signal tracking method for a satellite navigation system receiver as described in claim 1, characterized in that, The step of performing coherent integration processing on the intermediate frequency carrier signal output by each antenna element based on the local carrier signal to obtain the coherent integration value of each intermediate frequency carrier signal includes: Based on the local carrier signal, target signal extraction and phase alignment are performed on the intermediate frequency carrier signal output by each antenna element to obtain a baseband complex signal; The complex domain superposition of each baseband complex signal is performed to obtain the coherent integral value of each intermediate frequency carrier signal.

3. The signal tracking method for a satellite navigation system receiver as described in claim 1, characterized in that, The step of establishing the carrier signal state model and carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal based on the coherent integral value includes: Establish the state vector and state transition matrix of the intermediate frequency carrier signal, and convert the state vector and state transition matrix into the state equation of the extended Kalman filter carrier signal; establish the state noise covariance matrix based on the integration time, the angular frequency of the intermediate frequency carrier signal, and the power spectral intensity of the state drive noise of the numerically controlled oscillator. Based on the carrier signal state equation and the state noise covariance matrix, a carrier signal state model is constructed. Based on the coherence integral value, the carrier signal observation equation of the extended Kalman filter is set; based on the carrier-to-noise ratio of the intermediate frequency carrier signal, the observation noise covariance matrix is ​​set. Based on the carrier signal observation equation and the observation noise covariance matrix, a carrier signal observation model is constructed.

4. The signal tracking method for a satellite navigation system receiver as described in claim 3, characterized in that, The step of setting the carrier signal observation equation of the extended Kalman filter based on the coherent integral value includes: The branch coherence matrix is ​​obtained based on the coherence integral value, the integration time, and the carrier phase of the intermediate frequency carrier signal; The observation noise matrix is ​​obtained based on the coherent integral value of the co-directional observation noise in the co-directional branch and the orthogonal observation noise in the orthogonal branch. Based on the branch coherence matrix and the observation noise matrix, the carrier signal observation equation of the extended Kalman filter is set.

5. The signal tracking method for a satellite navigation system receiver as described in claim 3, characterized in that, The step of performing extended Kalman filter iterative calculation on the coherent integral value based on the carrier signal state model and the carrier signal observation model to obtain the state vector estimate of each intermediate frequency carrier signal includes: Based on the state noise covariance matrix, the carrier signal state equation, the state vector estimate of the previous time step, and the posterior error variance matrix of the previous time step, the single-step state prediction value and the prior error variance matrix of the current time step are obtained. Based on the carrier signal observation equation, the coherent integral value is transformed to obtain the linearized observation matrix after the linearized observation function; The Kalman gain is obtained based on the prior error variance matrix, the observation noise covariance matrix, and the linearized observation matrix. Based on the single-step state prediction value, the Kalman gain, the carrier signal observation equation, and the linearized observation matrix, the coherent integral value is estimated to obtain the estimated state vector value at the current time. Then, based on the Kalman gain, the linearized observation matrix, and the prior error variance matrix, the posterior error variance matrix at the current time is estimated to obtain the posterior error variance matrix at the current time.

6. The signal tracking method for a satellite navigation system receiver as described in claim 5, characterized in that, The linearized observation matrix is ​​set as a matrix relating to the coherent integral value, the integration time, the total number of antenna elements, and the estimated phase value of the local carrier signal.

7. The signal tracking method for a satellite navigation system receiver as described in claim 1, characterized in that, The step of performing multi-channel carrier signal joint tracking on the coherent integral value based on the local carrier signal to obtain the dynamic phase weight value of each antenna element includes: Based on the coherent integral value, an initial reference signal for each antenna element is obtained, and based on the initial reference signal, an initial phase weight value for the coherent integral value is obtained. Based on the local carrier signal and the initial phase weight value, the initial reference signal is dynamically iteratively updated to obtain the dynamic reference signal of each antenna element at the current moment; Based on the dynamic reference signal at the current moment, the initial phase weight value is dynamically iteratively updated to obtain the dynamic phase weight value of each antenna element at the current moment.

8. The signal tracking method for a satellite navigation system receiver as described in claim 7, characterized in that, The step of obtaining the carrier phase residual of each antenna element at the current moment based on the dynamic phase weight value, and based on the carrier phase residual at the current moment, includes: Cross-correlation is performed between the intermediate frequency carrier signal of any one of the antenna array elements and the combined reference signal constructed by weighted combination of the remaining antenna array elements; The phase difference between the intermediate frequency carrier signal and the combined reference signal is extracted to obtain the carrier phase residual of each antenna element at the current moment.

9. The signal tracking method for a satellite navigation system receiver as described in claim 1, characterized in that, The step of correcting the phase of the corresponding state vector estimate based on the carrier phase residual at the current moment to obtain the carrier signal phase estimate of the intermediate frequency carrier signal includes: The phase sum between the carrier phase residual at the current moment and the corresponding state vector estimate is calculated to obtain the carrier signal phase estimate of the intermediate frequency carrier signal.

10. A signal tracking system for a satellite navigation system receiver, used to implement the signal tracking method for the satellite navigation system receiver according to any one of claims 1-7, characterized in that, The system includes: a coherent integration processing module, an extended Kalman filter processing module, a phase weight value dynamic update module, and a phase correction module; The coherent integration processing module is used to obtain a local carrier signal based on the carrier phase residual of each antenna element at the previous moment, and to perform coherent integration processing on the intermediate frequency carrier signal output by each antenna element based on the local carrier signal to obtain the coherent integration value of each intermediate frequency carrier signal. The extended Kalman filter processing module is used to establish a carrier signal state model and a carrier signal observation model corresponding to the extended Kalman filter of the intermediate frequency carrier signal based on the coherent integral value, and to perform extended Kalman filter iterative calculation on the coherent integral value based on the carrier signal state model and the carrier signal observation model to obtain the state vector estimate of each intermediate frequency carrier signal. The phase weight value dynamic update module is used to perform multi-channel carrier signal joint tracking on the coherent integral value based on the local carrier signal to obtain the dynamic phase weight value of each antenna element. The phase correction module is used to obtain the carrier phase residual of each antenna element at the current time according to the dynamic phase weight value, and to correct the phase of the corresponding state vector estimate according to the carrier phase residual at the current time, so as to obtain the carrier signal phase estimate of the intermediate frequency carrier signal.

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